diff --git a/include/osmocom/msc/a_iface.h b/include/osmocom/msc/a_iface.h
new file mode 100644
index 0000000..a49ede2
--- /dev/null
+++ b/include/osmocom/msc/a_iface.h
@@ -0,0 +1,76 @@
+/* (C) 2017 by Sysmocom s.f.m.c. GmbH
+ * All Rights Reserved
+ *
+ * Author: Philipp Maier
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#pragma once
+
+#include <osmocom/msc/a_reset.h>
+
+/* A struct to keep a context information about the BSCs we are associated with */
+struct bsc_context {
+	struct llist_head list;
+
+	/* Holds a copy of the sccp address of the BSC,
+	 * this address will become known as soon as
+	 * a remote BSC tries to make a connection or
+	 * sends a RESET request via UNIDATA */
+	struct osmo_sccp_addr bsc_addr;
+
+	/* Holds a copy of the our local MSC address,
+	 * this will be the sccp-address that is associated
+	 * with the A interface */
+	struct osmo_sccp_addr msc_addr;
+
+	/* A pointer to the reset handler FSM, the
+	 * state machine is allocated when the BSC
+	 * is registerd. */
+	struct a_reset_ctx *reset;
+
+	/* A pointer to the sccp_user that is associated
+	 * with the A interface. We need this information
+	 * to send the resets and to send paging requests */
+	struct osmo_sccp_user *sccp_user;
+};
+
+/* Initalize A interface connection between to MSC and BSC */
+int a_init(struct osmo_sccp_instance *sccp, struct gsm_network *network);
+
+/* Send DTAP message via A-interface */
+int a_iface_tx_dtap(struct msgb *msg);
+
+/* Send Cipher mode command via A-interface */
+int a_iface_tx_cipher_mode(const struct gsm_subscriber_connection *conn,
+			   int cipher, const const uint8_t *key, int len, int include_imeisv);
+
+/* Page a subscriber via A-interface */
+int a_iface_tx_paging(const char *imsi, uint32_t tmsi, uint16_t lac);
+
+/* Send assignment request via A-interface */
+int a_iface_tx_assignment(const struct gsm_trans *trans);
+
+/* Send clear command via A-interface */
+int a_iface_tx_clear_cmd(struct gsm_subscriber_connection *conn);
+
+/* Clear all subscriber connections on a specified BSC
+ * (Helper function for a_iface_bssap.c) */
+void a_clear_all(struct osmo_sccp_user *scu, const struct osmo_sccp_addr *bsc_addr);
+
+/* Delete info of a closed connection from the active connection list
+ * (Helper function for a_iface_bssap.c) */
+void a_delete_bsc_con(uint32_t conn_id);